People with the face covered clash with riot police near Mexico City's International Airport, in Mexico City, capital of Mexico, on Nov. 20, 2014. As part of the commemoration of the 104th anniversary of the beginning of Mexican Revolution, various social and student organizations participated in protests, marches, and blockades in the Airport area and in different parts of the country, calling for the safe return of the 43 missing students of the Raul Isidro Burgos Rural Teachers' College of Ayotzinapa, Guerrero, disappeared on September 26 in Iguala, Guerrero, according to local press. (Xinhua/Pedro Mera)